Many sports enthusiasts wear spiked or cleated shoes. The spikes give added resistance to slipping or sliding on soil, grass or other surfaces. The spikes thus improve performance and reduce the risk of injury. This type of shoe can be used in running, golf, football, baseball, soccer or other outdoor sports.
However, the sports enthusiast may need to periodically walk/run over a paved area or enter a building. Spiked shoe removal may not be practical. Carrying conventional shoe replacements may not be an option during play and walking barefoot may not be acceptable. Change of shoes, even if practical, consumes time. If shoes are soiled, enthusiasts may also be required to wash his or her hands, further consuming time. In addition to the comfort and convenience of the sports enthusiast, walking on spikes may damage the spikes, shoes, carpets, etc.
One approach to overcoming this problem has been removable cleats or spikes. Cleats or spikes are attached to a conventional or specially adapted shoe using straps or other means. This allows the sports enthusiast to easily remove spikes or cleats prior to walking on indoor or prepared surfaces. However, this approach requires wearing conventional shoes during game or compromises in sports shoe design to allow removable feature. These compromise shoes can not be as light or supporting a the sports shoes they replace because of the addition of removable attachment devices. Inadvertent loss of cleats or spikes could also be unsafe.
The closest prior art to the invention that is known to the applicant are overshoes, outer soles or cleat guard protective devices as shown in U. S. Pat. Nos.: 3,858,336; 2,958,963; and 3,566,488. Other types of overshoe protection devices are shown in U. S. Pat. Nos.: 4,693,019; 4,258,483; 3,812,603; 3,020,654; and 2,032,052, as well as German Pat. No. 3044-032. These prior art overshoe protective devices provide a raised platform attached to the sole and heel portions of the sports shoe and has a cavity or cavities for the spikes or cleats of the sports shoe to protrude into. Platform is generally made from plastic, rubber or other elastic material sometimes with hard inserts (see U. S. Pat. Nos.: 3,858,336; 2,958,963; 3,566,488; 3,020,654; and 4,693,019) but also may be made from generally rigid materials (see German Pat. No.: 3,044,032 and U. S. Pat. No. 4,258,483) or either/combination of materials (see U. S. Pat. No.: 2,032,052; and 3,812,603).
These prior art overshoe protective devices have serious limitations. Major limitations can be classified into two categories. The first limitation category is related to the need to balance the rigid vertical support objective (to maintain the spikes off the ground and react against normal shoe forces) with the flexibility objective (to bend with the shoe and adapt to different shoe types and sizes). The need for rigid vertical support results in increased height. This increased height may be compounded by any flexibility of the material which can cause compression under maximum load, but will further increase height under less than maximum vertical load. This added height can also create balance problems for the user.
The second major limitation category is related to the need to balance lateral support objectives (to provide a rigid platform to resist side loads) with the need for adaptability (interchangeability of slipover with many sport shoes). Some prior art designs provide large cavities for the spikes to protrude into, allowing many different spike patterns and shoe sizes to be accommodated. However, these largo cavities limit the amount of structure that can transfer lateral forces. Other designs provide flexible structures to adapt to the spike patterns, but the flexible material is not able to provide the same degree of lateral support without deformation. This lateral support problem is compounded by the increased height required to provide for lateral support. Significant lateral deformation over the increased height may be difficult to avoid while maintaining the ability to adapt to different shoe patterns and sizes.
What is needed is an overshoe protective device that provides firm lateral and vertical support to prevent damage to the spikes, shoe and user, while maintaining the ability to adapt to the variety of shoe sizes and spike patterns in current use